@Aquaria: Is the weather still nice where you live? Rather than take him out to dinner, which could use the majority of the $100, I would pack up a romantic picnic basket. That would free up more $ for his gift.

If you tell us something about his interests, we might be able to come up with some ideas.

Got my FI the Game of Thrones books for his birthday, he’s so into them. I’ve also gotten him a mini food processor and a cookbook, cologne, tickets to a football game, shoes… I usually try to get him something practical. Something I know he’ll use everyday or at least very often.